By then the Communists had been exposed and began to preach to the locals. Their morale was high and they expected it'd take a long time until the military returned. They didn't realize that the Army was preparing operation Sucuri, a brilliant counterinsurgency campaign. Planning was transferred from the regular hierarchy to military intelligence. A small number of men from the political intelligence service (DOI) and the 3rd Motorized Infantry Brigade were acclimated to rural life in estates around Brasília, took up aliases and covertly arrived in the area. They blended into the local population and became merchants, sometimes even selling weapons to the insurgents to appear trustworthy. This allowed them to meticulously compile information on guerillas and peasants, drafting maps and building up 400 individual profiles by September 1973.
This was followed by operation Marajoara in October. A few hundred men taken from the Army's elite formations arrived under total silence with no identification and immediately imposed a curfew and violently coerced several peasants to collaborate. With plenty of intel, they killed off the militants' command hierarchy, reducing it to isolated pockets in the jungle. Those were systematically hunted down and liquidated until October 1974. Large numbers of prisoners were taken, but they were all executed. Only two communists escaped, one of whom lived in hiding until 1996.

Military authorities imposed total media silence about the event (though word of it would end up leaking to the wider world) and remained quiet for decades afterwards. A cleanup operation in 1975 destroyed or hid a number of corpses, and agents still made occasional visits to eliminate traces in the following years. The government only spoke of it once: President Geisel mentioned on a briefing to Congress in March 1975 that attempts were made to organize "guerilla bases in the remote and unprotected hinterland", but they were "completely reduced".

The second event was simpler. The Party was set to hold an important meeting on São Paulo in December 1976 for serious discussions about the war, but an imprisoned militant tipped off the government in exchange for $ 150 thousand. They were ambushed, with 3 Party members dead and 5 imprisoned. This decapitation strike initiated the Party's transition to a moderate player in electoral politics.

So onto the film. It is part political piece, part documentary and part reenactment. It builds its narrative by alternating between four sequences:

-Scenes of poverty, raw materials extraction and trade in the Amazon and the Third World play while someone rants about how foreign investment is literally theft, commodity exports are evil and imperialism is to blame for the global south's poverty. It is, of course, implied that foreign trade must be closed and import substitution industrialization attempted. It's unremarkable, as this discourse is widespread and has been popular for a century.
-The heart of the film: interviews with old militants, aswell as a few modern activists. They are spontaneous -as, after all, they're not acting- and provide nearly all of the information. A notable presence is José Genoino, former PCdoB militant who joined the PT and found himself caught in the Mensalão scandal. He was condemned to 6 years and 11 months in jail over active corruption and criminal association in 2012, but got freed as part of a Christmas presidential pardon in 2014. As a mainstream politician, he's the easiest to understand. At one point he even cites the American Constitution as an argument for armed struggle against a government. Though looking back he doesn't approve of the war, and the other interviewees are similarly skeptical.
-Two generals on a featureless room with a black background discuss the war, and their repression of subversive activity in general. They are relutanct over the morality of their actions but ultimately embrace them and deem them effective. This part has the only believable acting in the film. There's some emotion to their discussion.